Mechanics, state revise oil-change mileage numbers

For years, the conventional wisdom said you should change your car's oil every three months. Now the conventional wisdom may be changing. There's a new push to get car owners to wait longer.

To take proper care of your car, you want to have the oil changed regularly. But how often is that? The state of California says there's no need to do it too often.

"A lot of California drivers are still changing their motor oil more frequently than necessary," said Mark Oldfield, CalRecycle. "A lot of people are still going by the old 3,000-mile standard when many of today's cars can actually go 5,000, 7,500, or even 10,000 miles between oil changes."

CalRecycle, the agency that makes sure everything is recycled properly, has embarked on a campaign called "Know Your Number" -- In other words, know how many miles your car can actually go between changes.

The general 3,000-mile rule is out of date.

"Three-thousand miles is excessive. The new oils and filters and engines, they're way better than they used to be," said mechanic Jim Ward.

Ward is a fourth-generation mechanic and owner of Ward Service in Monrovia. His general rule of thumb is 5,000 miles these days. He says going longer might not hurt -- or it could.

"We find that we're adding a lot of oil to cars now, and in between, so people aren't getting them checked," said Ward.

And if the oil level gets low, the engine can suffer.

"When these people are waiting longer between services, we're doing a lot more timing chains now, we're doing a lot more valve jobs, we're doing a lot of lifters, internal engine problems," said Ward.

The state's goal is not getting rid of perfectly good oil, even though it does get recycled.

"If we reduce the amount of oil we're using at the front end, we could save 10-, 20-, maybe even 30 million gallons of oil a year just here in California," said Mark Oldfield.

It's not just an environmental issue, it's also a financial one. As the price of crude oil has risen in the past decade, so has the price of motor oil. Regular oil, you'll pay between $4 and $6 a quart, and synthetic oil, which more and more cars now use, $9 to $10 per quart.

Some modern high-end cars can tell you when the oil needs changing to make it easier.

But the best method is still to look in your owner's manual. If you don't have one, the CheckYourNumber web site can help you get the information.

And as oil and engines have improved, doing it more often isn't as pragmatic as it once was. It's now just money down the drain.